４ - ３ Operation Regardless of the type of subroutine, every subroutine is executed as a synchronous operation after an event is driven. All other processings stop until the subroutine process ends. A global subroutine has configuration for variable asynchronous operation of an event. The subroutine processing which is set on the event’s action with this configuration is implemented as asynchronous operation. When a global variable that is mapped by a controller is accessed, communication is started. It happens because current variable of a controller’s main unit is updated when the code accesses. The following shows interior behaviors in NA while a subroutine is executed.
Precautions for Correct Use Frequent repetition processing (e.g. For Next) or access to controller's global variable may slow down screen update processing. Asynchronous configuration for events will prevent it. 18 ■NA Update Update screen communication data Update Update data-2 screen-1 Call subroutine Update-2-1 Update data-3 Refreshed on each occasion Subroutine Return Update-2-1 Update data-3 subroutine Call subroutine Refreshed on each occasion Asynchronous subroutine Return subroutine Update-3 Update data-4 Update-4 ■Controller Peripheral service Update data-2 Update data-3 Refreshed on ea occasion Update-3 Update data-4 Update data-3